ERIC EJ1083081: Development and Validation of Scientific Literacy Achievement Test to Assess Senior Secondary School Students' Literacy Acquisition in Physics

2015·1.1 MB·English

by  ERIC

Journal of Education and Practice www.iiste.org
ISSN 2222-1735 (Paper) ISSN 2222-288X (Online)
Vol.6, No.7, 2015

Development and Validation of Scientific Literacy Achievement
Test to Assess Senior Secondary School Students’ Literacy
Acquisition in Physics

A.A Adeleke1* E.O Joshua2 (PhD)
1. Department of Teacher Education, University of Ibadan, Nigeria
2. Department of Physics, University of Ibadan, Nigeria
* E-mail of the corresponding author: [email protected]

Abstract
Physics literacy plays a crucial part in global technological development as several aspects of science and
technology apply concepts and principles of physics in their operations. However, the acquisition of scientific
literacy in physics in our society today is not encouraging enough to the desirable standard. Therefore, this study
focuses on development and validation of scientific literacy achievement test to assess senior secondary school
students’ literacy acquisition in physics. The study adopted descriptive survey research design in which a total of
two hundred and six (206) students from 8 secondary schools in Ibadan North and Oorelope local government
areas of Oyo state were assessed. The schools were selected using proportional random sampling techniques.
The achievement test titled, Physics-Scientific Literacy Achievement Test (P-SLAT) that had been validated by
experts and tested to have Cronbach’s alpha and Split-half reliability coefficient of 0.82 and 0.80 respectively.
The result of the administered test was collated and coded for analysis, which was carried out with the aid of
SPSS 17 package and Microsoft word excel while both descriptive, such as simple percentage and charts were
adopted. The result of the research findings shows that. The overall acquisition of scientific literacy in physics
among the students is average. The achievement test used has an average reliability coefficient of 0.70 based on
Cronbach’s alpha, Kuder-Richardson (KR20) and Split-Half method. Based on the three psychometric properties
(reliability, item difficulty and discrimination) considered in item analysis of the achievement test developed in
the study, eighteen (18) items which is equivalent to 72% of the total items form the validated achievement
test.These findings provide vivid evidence for recommendations for various examining bodies by subjecting
multiple choice items to psychometric tests to ascertain and improve items’ quality in order to obtain a reliable
and valid test result. It was also suggested for prospective researchers in the same or related field of study that
this research should be carried out in all secondary schools in Oyo state in order to have a more generalised
result on the level of secondary school students’ acquisition of scientific literacy in physics.
Keywords: Scientific literacy, Item analysis, difficulty index, discrimination index, reliability coefficient.

1. Introduction
Science is made up of huge number of fields such as Physics, Chemistry, Biology and lots more. According to
Folajimi and Emmanuel (1999), in recent times, at the secondary education level, the integrated science
curriculum is designed to introduce all the students to the whole of science which would provide relevant
foundation on which the senior secondary will build careers in science or science related disciplines, while the
senior secondary level pupils are introduced to different disciplines. In order to realize this, emphasis on school
science has been shifted to realization of scientific literacy acquisition.
Among the two broad purposes of science education is to promote scientific literacy among citizens on
matters directly affecting their own lives and the society so that they can make decisions based on information
and understanding. This is essential for the sustainable development of a modern, technological society. The
second acclaimed purpose of science education is to build up technological capability by equipping the future
workforce with essential science-based knowledge and skills, and by preparing students for scientific disciplines
in higher education and science-related careers. Given the potential benefits, the provision of quality science
education to all children will have far reaching consequences on a country's development prospect.
Akindehin (1996) identified and measured acquisition of scientific literacy based on the following five
(5) skills which he considered as scales relevant for measuring scientific literacy in physics: The Science
Knowledge I (SKI), Science Knowledge II (SKII), Science Knowledge III (SKIII), Science Habit of the Mind
(SHM), Solving Problems and Conducting Inquiries (SPC). The objectives measured by these skills respectively
include information about nature phenomena that are usually emphasized in physics lessons; fundamental
concepts, principles and theories in physics; nature of science, its characteristics such as empirical and
theoretical methods and philosophy that distinguish science from other human activities; ability to think
scientifically and the inclination to do so beyond the confines of the science classroom; and students interaction
with the natural world.
As a matter of fact, the acquisition of scientific literacy in school science teaching is one of the most
28
Journal of Education and Practice www.iiste.org
ISSN 2222-1735 (Paper) ISSN 2222-288X (Online)
Vol.6, No.7, 2015

widely accepted educational goals. The world over has its aims at making the learners able to cope and
contribute to scientific enterprises from day-to-day in a world dominated by science and technology (Folajimi
and Emmanuel, 1999).
According to Halliday, Resnick and Walker (2008) Physics, like all other sciences is based on
experimental observations and quantitative measurements. The main objective of physics is to find the limited
number of fundamental laws that govern natural phenomena and to use them to develop theories that can predict
the results of future experiments. The fundamental laws used in developing theories are expressed in the
language of mathematics, the tool that provides a bridge between theory and experiment. When a discrepancy
between theory and experiment arises, new theories must be formulated to remove the discrepancy. Many times,
a theory is satisfactory only under limited conditions; a more general theory might be satisfactory without such
limitations.
Classical physics, according to Halliday, Resnick and Walker (2008) means all of the physics
developed before 1900, includes the theories, concepts, laws, and experiments in classical mechanics,
thermodynamics, and electromagnetism. Important contributions to classical physics were provided by Newton,
who developed classical mechanics as a systematic theory and was one of the originators of calculus as a
mathematical tool. Major developments in mechanics continued in the 18th century, but the fields of
thermodynamics and electricity and magnetism were not developed until the latter part of the 19th century,
principally because before that time the apparatus for controlled experiments was either too crude or unavailable.
A new era in physics, usually referred to as modern physics, began near the end of the 19th century.
Modern physics developed mainly because of the discovery that many physical phenomena could not be
explained by classical physics. The two most important developments in modern physics were the theories of
relativity and quantum mechanics. Einstein’s theory of relativity revolutionized the traditional concepts of space,
time, and energy; quantum mechanics, which applies to both the microscopic and macroscopic worlds, was
originally formulated by a number of distinguished scientists to provide descriptions of physical phenomena at
the atomic level (Halliday, Resnick and Walker, 2008).
Scientists constantly work to improving our understanding of phenomena and fundamental laws, and
new discoveries are made every day. In many research areas, a great deal of overlap exists between physics,
chemistry, geology, and biology, as well as engineering. Some of the most notable developments are; numerous
space missions and the landing of astronauts on the Moon, micro circuitry and high-speed computers, and
sophisticated imaging techniques used in scientific research and medicine.
It was further emphasized by Halliday, Resnick and Walker that the impact which such developments
and discoveries had on our society has indeed been great, and it is very likely that future discoveries and
developments will be just as exciting, challenging and of great benefit to humanity if scientific knowledge of
physics is improved.
Physics literacy is crucial for effective living in the modern age of science and technology. Given its
application in industry and many other professions, it is necessary that every student is given an opportunity to
acquire some of its concepts, principles and well-grounded skills. Unfortunately, the teaching and learning of
physics has been fraught with challenges which prevent many students from acquisition of appropriate scientific
skills generally and that of physics in particular. Despite the fact that the philosophy, objectives and content of
physics curriculum have been adjudged by professionals in the field to be satisfactory enough, yet its
implementation has fallen short of expectation because of the lack of sufficient number of qualified physics
teachers among other factors which affect acquisition of proper scientific skill teaching in order to enhance
meaningful learning whereas the nature of the subject thereby appearing to evoke difficulty.
Valladolid (2010) emphasised that in the new framework of instruction, student is the primary agent of
learning. The framework includes the following areas: the students’ learning process, the teacher’s work, the
students’ learning environment, and assessment of students learning. This framework emphasizes the
interrelationship between students’ learning and assessment which can be verified through achievement test or
other form of assessment procedures.
A test refers to a set of questions or items designed and to be responded to by one or a group of
individuals within a specified period of time. Tests are used mainly as measures of achievement, to show how
much an individual has learnt or not learnt in an aspect of instruction to which he has been exposed. It is
therefore a major instrument in the process of evaluation. It then makes it imperative for us as a teacher or
teacher trainer to be conversant with all forms of test and testing procedures (Aina, 2006).
According to Charles (2007), the importance of tests in educational settings need not be over-
emphasized as tests are used to improve an individual, inform him of how he is faring in a learning situation and
to develop his intellect. Achievement tests are most useful in educational settings for analysing causes of
academic failure, evaluating learning outcomes, curriculum evaluation, and motivation of learners as well as
vocational counselling. Charles further argued that whenever we want to evaluate students against criteria that go
beyond a single teacher's classroom and those teachers’ conceptions of what should be taught. There is need for
29
Journal of Education and Practice www.iiste.org
ISSN 2222-1735 (Paper) ISSN 2222-288X (Online)
Vol.6, No.7, 2015

a standardized test in addition to having norms - that is, bases for interpreting scores in terms of other students’
scores because standardized tests are usually more carefully constructed than teacher made tests and the
construction is carried out by experts, using the technical, statistical and research knowledge of the testing field.
Hence, standardized test are different from conventional school (teacher-made) tests because they have norms,
better constructed by experts, accompanied by manuals and have good psychometric properties.
Standardized tests usually are accompanied by detailed instructions about how the test should be
administered - the exact directions to be given to students, the time limits (if any) and the ways in which
the teacher should handle any special problem that may arise. All these essential information are contained in an
accompanying booklet called the test manual. Based on the above argument one can deduce that standardized
test is significantly different from the teacher-made test in terms of the content measured, student preparation,
quality of the items, administration, scoring as well as interpretation.
Therefore, the functions of standardized test are those roles which it plays in a wide range of situations
in educational, social, industrial or clinical contexts. Hence, one should however note that the usage of
standardized tests overlap considerably since we can use one type of test in a number of situations perhaps a
number of tests can be used for one particular situation.
The types of the teacher-made achievement test used in the Nigerian educational system are broadly
categorised into two: the essay and objective type. These two broad categories are usually conveniently
compared on the following parameters: ability being measured, coverage of the test, ease of preparing, scoring
and motivation of learners. The steps in constructing achievement tests are diverse but sequential. The first
which is a statement of objective must be done in terms of student behaviour, with an active verb, that is
observable and must be realistic. Other steps include the specification of content to be covered, development of
the test blueprint in which the content should be restricted to the topic areas covered and constructing
achievement tests, which include: generation of items, item analysis, establishment of psychometric properties
and norms. The test blue print is a two-fold table that shows the distribution of the items in a test, covering the
course content and tapping the scientific skills to be measured. To make the blue print an effective guide to
enable one ascertain content coverage, the type of items desired, the length of the test and the difficulty level of
the items.
In constructing teacher-made tests, some guidelines are general to teacher-made tests like essay and
objectives test items which include drafting the exercises well in advance, having the items critiqued by a
colleague, generation of surplus items and keep the test blue-print as a constant guide. The items should be
distributed across all cognitive skills: knowledge, comprehension, application analysis, synthesis and evaluation
or other specific skills to be measured. This is done with due cognizance of the Bloom’s Taxonomy of
Educational Objectives which encourage test constructors to tap a range of cognitive skills from knowledge
through synthesis to evaluation (Charles, 2007). Test scoring is the process of obtaining data from testees’
protocols. Scoring can be done by Hand or by Machine while interpretation is the process of organizing data or
test scores in order to help the process of making deductions by adopting the micro or macro model of test
interpretation.
The setting of examinations in various subjects by an examination board external to the school is
common around the world. The examinations are taken at the end of a course, or school curriculum, and
determine success or failure for future advancement and are often referred to as once only, high stakes,
examinations. These can involve objective testing, often multiple choice (MCQ) items, and/or more subjective
questions where students construct the responses themselves. Where MCQ items are involved, the scoring is
dichotomous, undertaken by machine and reliability is less of a concern than validity of the items chosen. As it is
generally accepted that valid instruments are important, essay-type questions still remain an obvious choice for
evaluation of knowledge. Unfortunately, allocating marks for essay-type, student free-response questions can be
very unreliable, unless marking systems are well developed (Baird, Greatorex, & Bell, 2004).
Charles (2007) opined that a number of guidelines apply to all the formats. Among these are;
commensurate difficulty level of items, consistency of the correctness of answer tapping of salient content area
and independence of each item. Like all measuring instruments, achievement test is supposed to reveal the best
possible results. This can be attained by ensuring that certain conditions are involved with the testing process at
their optimum. Choices of hall and advance preparation are some of these factors as the venue must be
environmentally conducive to elicit the desired response. Advance preparation in terms of the test materials is
essential.
Based on the above premise, the role of test in evaluation cannot be brushed aside. It is a major
instrument for evaluation. Because, from testing results data are obtained which are formulated into
measurements while the judgment or decisions made from such formulations and other measured observation
produces evaluation. Therefore, test and testing processes cannot be by-passed in the process of evaluation.
The psychometric properties of a test refer to the qualities expected of a test and basic desirable
qualities that a test must possess to be deemed satisfactory. These qualities referred to as the psychometric
30
Journal of Education and Practice www.iiste.org
ISSN 2222-1735 (Paper) ISSN 2222-288X (Online)
Vol.6, No.7, 2015

properties of a test hinge on the validity and reliability of the test. Validity and reliability are important
psychometric properties in the literature of educational measurement and evaluation with the former being the
more important as reliability is an estimate. The relationship between validity and reliability is that, a test may be
reliable but not valid. But a test may not be valid unless it is reliable. Hence, a test must possess both in order to
be deemed satisfactory for testing purposes.
Validity refers to the extent to which a test measures what it is supposed or purported to measure
operationally, the extent to which the results of an evaluation programme serve the particular uses for which they
are intended. In other words, it is the degree to which correct inferences may be drawn from test scores. If the
results are to be used to describe pupil achievement, one would like them to represent the specific achievement
we wish to describe, and to represent nothing else. The desires for valid achievement test in this regard are like
that of the lawyer in the court room who wants the truth, the whole truth and nothing but the truth. Hence,
validity is a matter of degrees which does not exist in an all-or-none basis. Thus, validity is best considered in
terms of categories that specify degree such as high validity, moderate validity or low validity (Charles, 2007).
A test is said to be valid to the degree that it measures what it claims to measure, or, in the case of
predictive validity, to the extent that it predicts accurately such types of behaviour as academic and job
success/failure, as well as stability or instability under stress. Tests are often validated by correlating test scores
against some outside criteria, which may be scores on tests of accepted validity, successful performance or
behaviour, or the expert judgment of recognized authorities (John W. Best, James V. Kahn, 1959).
Psychometricians believe that there is so much problem in establishing validity that the following
characteristics may be used to describe validity types; Concurrent, Criterion-related, Congruent, Discriminant,
Construct, Ecological, Content, Face Convergent Factorial, Predictive, Intrinsic et cetera (Charles, 2007).
Validity is the consistency of test scores and the extent which tests measure what they are originally
designed for. Very many types of these qualities abound, and they can all be estimated to ensure that tests
possess the qualities that will make them provide us with dependable scores. Reliability is usually taken to mean
the reproducibility of scores on another occasion. Reliability has been defined by (Berkowitz, Wolkowitz, Firch,
& Kopriva, 2000) as the degree to which test scores for a group of test takers are consistent over repeated
applications of a measurement procedure and hence are inferred to be dependable and repeatable for an
individual test taker. An index of reliability of a test for a given population can be taken to be the ratio of true
score variance to observed score variance (Dimitrov, 2002). True scores cannot be directly determined and hence
the reliability is an estimate. And of course, this assumes that the scores were obtained from a test that was seen
as sufficiently valid for the reliability of the results to have any meaning at all. A very reliable Physics test would
be totally out-of-place as a reliably instrument for the determination of history ability! But if validity is at an
acceptable and interpretable level, then reliability is an important consideration and challenge facing all
examination boards as well as educational evaluators (Brooks, 2004).
In statistics, the Kuder-Richardson Formula 20 (KR-20) first published by Kuder, G.F. & Richardson,
M.W. in 1937 is a measure of internal consistency (reliability) for measures with dichotomous choices. Kuder-
Richardson formula has two versions (KR-20 and KR-21) for achievement and psychological test items
respectively. These reliability techniques were named after its two developers (Kuder and Richardson).
The formula for estimating reliability is given by:

Where n = number of test items, SD2 = variance of scores on the test [square of the SD (standard
deviation)], P = proportion of testees who responded correctly, Q = proportion of testees who responded wrongly.
Unlike KR-20; KR-21 formula assumed that all items comprise equal difficulty, so it is peculiar to
psychological test reliability estimation. The formula for calculating KR21 is given by:

Where n = number of items in the test, M = mean of the scores on the test, SD2 = variances of scores
on the test [square of the SD (standard deviation)] (Wiseman, 1999 in Sabri, 2013).
Lee Joseph Cronbach (1916-2011) is a prominent American Psychologist and Mathematician who
developed one of the current and most acceptable methods of determining (internal consistency) reliability of
measuring instruments such as an achievement, aptitude, personality, attitude test, other forms of tests used in
science and social science research. This competition on reliability developed and came out with by Lee Joseph
Cronbach in 1951 is popularly called Cronbach’s alpha reliability test. The reliability analysis of items can be
carried out conveniently and easily on the popularly known Statistical Package for Social Science (SPSS) within
a very short period of time after the appropriate coding and entering of data has been done. Other methods of
determining reliability include; split half method and test-retest correlation method.
31
Journal of Education and Practice www.iiste.org
ISSN 2222-1735 (Paper) ISSN 2222-288X (Online)
Vol.6, No.7, 2015

Adeleke (2010) opined that the greater the number of similar items, the greater the internal consistency.
That’s why a researcher sometimes gets very long scales asking a question a myriad of different ways, so that
addition of more items results to a higher Cronbach’s alpha coefficient. He added that alpha of 0.80 is considered
as a reasonable benchmark. Cronbach’s alpha reliability coefficient is given by the formula;

Where α = estimate of Cronbach’s alpha reliability, K = Number of items and σ2 = Variance, σ =
Standard Deviation.
The implications of item analysis are significant for achievement testing, for example item difficulty
and discrimination index. The difficulty index is important because it helps to know how well students have
acquired the knowledge they are supposed to. The difficulty of a test actually varies with its use. A routine end
of term test needs not to be difficult. But a competitive screening examination should be considerably of higher
difficulty level. The range of normal item difficulty index (P) is given by the following inequality expression
(0.4 ≤ P ≤ 0.7) = (40% ≤ P% ≤ 70%) which implies that items with difficulty index below 0.4, (0.4 to 0.7), and
above 0.7 is said to be difficult, moderate and simple for the target population respectively as represented in the
figure below.
P
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
0 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
%

Figure 1: Number line showing the range of normal item difficulty index
Sabri (2013) also reported that based on recommendations by Instructional Assessment Resources
(IAR), test items were classified into three categories in terms of level of difficulty as Easy (Above 0.90),
Moderate (0.20-0.90) and Difficult (below 0.20).
The discrimination index is used to measure the extent to which the test has distinguishes between
higher and lower students’ achiever groups. Nenty (2000) in Ojerinde (2013) opined that it indicates the degree
to which examinees’ response to an item varies with, or relates to their trait level or ability. Charles (2007) also
noted that discriminative index helps to remove or eliminate indiscriminate items since they serve little purpose
in the test while the distractor analysis helps us to eliminate the distractors which are ineffective. Ojerinde (2013)
further showed that in test development and item evaluation some items do have negative discrimination indexes
and this would have accounted for the low reliability encountered. Therefore, such items should be modified,
dropped or replaced. He further stressed that result has indicated that the Item Response Theory (IRT) method
used in analysing the Pre-test data on UTME Physics was more reliable than the Classical Test Theory (CTT)
approach.
Matlock-Hetzel (1997) also clarified two ways of determining discriminating power of test items, to be
exact the discrimination index and discrimination coefficient. Matlock-Hetzel (1997), Si-Mui and Rasiah (2006),
Mitra, Nagaraja, Ponnudurai and Judson (2009) and Boopathiraj and Chellamani (2013) defines item
discrimination as a measure used to discriminate between students in the top with that of the low group who
obtained the correct responses. Fundamentally, the discrimination index differentiates students who are
knowledgeable and those who are not, meticulously revealing top scorers and low scorers achievement in each
item. The value of discrimination index ranges between -1.0 to 1.0.
The challenges faced by scientific literacy assessment in general and physics literacy in particular
among other things include the poor acquisition of scientific literacy among secondary school students which
scholars have attributed to many reasons such as poor testing procedures with items that are deficient of essential
psychometric properties. Thus, in an attempt to address these infringing issues, a need is felt to develop and
validate a scientific literacy achievement test to assess Senior Secondary School Students’ acquisition of
scientific literacy in physics. The development of such assessment test would be coupled with appropriate Test
Blue-Print (table of specification) in order to find out to what extent has the five (5) aforementioned scientific
literacy skills identified by Akindehin (1996) been acquired by senior secondary students preparing for their
Senior School Certificate Examination. Also, it should be noted that because physics is taught at senior
secondary level of education which actually marks the foundation of physics knowledge in the first instance as a
complement and to build on the already built background during the integrated (now basic) science that serves as
introduction to some physics concepts, knowledge and skills. Therefore, this achievement test will give us a
picture and provide answer to the extent of achievement of the following objectives given by Nigeria
Educational Research and Development Council (NERDC, 2009) in the Nigeria Physics Curriculum document
for Senior Secondary Schools.
32
Journal of Education and Practice www.iiste.org
ISSN 2222-1735 (Paper) ISSN 2222-288X (Online)
Vol.6, No.7, 2015

1. provision of basic literacy in physics for functional living in the society;
2. acquisition of basic concepts and principles of physics as a preparation for further studies;
3. acquisition of essential scientific skills and attitudes as a preparation for technological application of
physics; and
4. stimulate and enhance creativity.

2. Purpose of the study
The purpose of the study was to develop and validate scientific literacy achievement test to assess senior
secondary school students’ literacy in physics, carry out item analysis (difficulty and discrimination index) and
estimate the reliability coefficient of the achievement test.

3. Research questions
The following research questions will be answered in the course of this study.
R : What is the overall acquisition of scientific literacy among the senior secondary school students?
Q1
R : What is the reliability of the scientific literacy achievement test items?
Q2
R : What is the difficulty index of the scientific literacy achievement test items?
Q3
R : What is the discrimination index of the scientific literacy achievement test items?
Q4

4. Research Method
4.1 Research design
The study is a descriptive survey research designed to develop and validate scientific literacy achievement test
that will be apt to assess senior secondary school students’ acquisition of scientific literacy in physics. The
descriptive survey research method is considered appropriate for this study as it would help to obtain first-hand
information regarding the students’ level of acquisition of scientific literacy in physics.
The population comprised of science students offering physics at the senior secondary school level
selected from private and public secondary schools in Oyo state. The students in the final class, senior secondary
school three (SS 3), were used because they had completed the senior secondary two and were therefore familiar
with the course content at the same time preparing for their Senior School Certificate Examination (SSCE).
The research sample used was made up of two hundred and six (206) students proportionally drawn
from 8 (eight) secondary schools from Ibadan-North and Oorelope local government areas of Oyo state. The
schools are strictly those that offered sciences particularly physics at the senior secondary school level.

4.2 Instrument
The research instrument titled “Physics - Scientific Literacy Achievement Test (P-SLAT)” was used for this
study. As shown in the table 1 (Test Blue-Print or Table of Specification) below, the instrument consists of 25
(twenty-five) objective test items developed by the researcher were designed with four options lettered A-D out
of which only one was the correct as the acceptable answer based on all the six (6) themes of physics identified
in the Nigeria Senior Secondary School Physics Curriculum and the five (5) scales identified by Akindehin
(1996) for measuring the acquisition of scientific literacy.
Table 1: Test Blue-Print (Table of Specification) for the Physics - Scientific Literacy Achievement Test
SCIENTIFIC LITERACY OBJECTIVES
S/N CONTENT AREA
SKI SKII SKIII SHM SPC TOTAL
1. Interaction of Matter, Space and Time 1 1 - 1 - 3
2. Conservation Principles 1 1 1 1 1 5
3. Waves: Motion without Material Transfer 1 1 1 1 1 5
4. Fields at Rest and in Motion 1 1 1 - 1 4
5. Energy Quantization and duality of Matter 1 - 1 1 1 4
6. Physics in Technology - 1 1 1 1 4
TOTAL 5 5 5 5 5 25

Scales for measuring Scientific Literacy Acquisition in Physics
Akindehin (1996) identified five (5) scales for measuring the acquisition of scientific literacy. The scales and the
corresponding scientific literacy objective measured by each scale are shown in the Table 2 below.
33
Journal of Education and Practice www.iiste.org
ISSN 2222-1735 (Paper) ISSN 2222-288X (Online)
Vol.6, No.7, 2015

Table 2: Descriptive, Information for Scientific Literacy Achievement Test
S/N SCALE NAME SCIENTIFIC LITERACY OBJECTIVES MEASURED
1. Science Knowledge I (SKI) Information about nature phenomena that are usually emphasized in
physics lessons.
2. Science Knowledge II (SKII) Fundamental concepts, principles and theories in physics.
3. Science Knowledge III (SKIII) Nature of science, its characteristics such as empirical and
theoretical methods and philosophy that distinguish science from
other human activities.
4. Science Habit of the Mind Ability to think scientifically and the inclination to do so beyond the
(SHM) confines of the science classroom.
5. Solving Problems and Students’ interaction with the natural world.
Conducting Inquiries (SPC)
Source: Akindehin, 1996

In the Table 3 below, sample items from each of the above scales are presented as used in the Physics - Scientific
Literacy Achievement Test (P - SLAT) developed for validation in this study.

Table 3: Sample Items for Each of the Scientific Literacy Scales
S/N SCALE NAME SAMPLE ITEM
1. Science Knowledge I A wave travelling from water to glass suffers a change in its speed at the
(SKI) common boundary. Which of the following properties explains this
observation? (A) Dispersion (B) Refraction (C) Interference (D)
Diffraction
2. Science Knowledge II Laws of refraction state the following except; (A) the incident ray, the
(SKII) refracted ray and the normal ray at the point of incidence all lie in the same
plane (B) [sin i / sin r] is constant for the media concerned (C) the incident
angle and the reflected angle are equal (D) refractive index (n) = speed of
light in vacuum / speed of light in the medium
3. Science Knowledge III The sagging of overhead electrical cables is the consequence of (A) linear
(SKIII) expansivity (B) superficial expansivity (C) cubic expansivity (D)
conductivity
4. Science Habit of the Which of the following reasons explains why the walls and ceilings of a
Mind (SHM) standard concert hall are usually covered with perforated pads? To (A)
increase the intensity of sound waves (B) increase the loudness of the
sound waves (C) reduce the effect of reverberation of sound waves (D)
decrease the frequency of sound waves.
5. Solving Problems and When the pressure of a fixed mass of gas in a bicycle pump is doubled at
Conducting Inquiries constant temperature, the volume of the gas in the pump is (A) doubled (B)
(SPC) halved (C) increased four times (D) unchanged.
Source: Akindehin, 1996

4.3 Procedures
The researcher visited the public and private secondary schools within Ibadan North and Oorelope local
government areas and administered the achievement tests to the Senior Secondary three (3) physics students after
which permission have been sought from the school principal and the physics teachers in charge. The students
were instructed to attempt all the question items to the best of their knowledge under the supervision of the
teachers in charge, researcher and his research assistant while the attempted copies of the achievement test items
were collected back immediately.

5. Results
5.1 Research question 1: What is the overall acquisition of scientific literacy in physics among senior secondary
school students?
34
Journal of Education and Practice www.iiste.org
ISSN 2222-1735 (Paper) ISSN 2222-288X (Online)
Vol.6, No.7, 2015

Table 4: Statistical summary of the students’ overall scientific literacy acquired
Total No. of
Mean Median Mode Range Variance Std. Deviation Total Item
Students
12.7 13.0 14.0 19.0 15.3 3.9 25 206

Table 4 above presents the statistical summary of the students’ score in the achievement test. The summary
reveals as a measure of central tendency to describe the students’ score that, the mean (average), median, mode
is 12.7, 13.0 and 14.0 respectively. By measure of dispersion, the range, variance and standard deviation is 19.0,
15.3 and 3.9 respectively.

30
24
25 22 22
19
20
y 15 15
c 14
n
e 15 12
u 11
q 10
Fre 10 7 6 8 9
3
5 2 2 2 2
1
0
22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3
Score

Figure 2: Graphical illustration of distribution of students’ score in the achievement test

The graphical illustration shown in figure 2 above presents the distribution students’ score (performance) as a
measure of overall acquisition of scientific literacy in physics among senior secondary school students based on
the assessment carried out by adopting the developed test, Physics-Scientific Literacy Achievement Test (P-
SLAT) comprising of twenty-five (25) question items, hence the maximum obtainable students’ score is 25. The
graph further reveals that the highest and lowest score is 22 and 3 respectively.

Figure 3: Bar chart illustrating the distribution of students’ score in the achievement test

Figure 3 above reveals that the mean, median and mode of the students’ score fall in to the same score interval. It
can be deduced that the overall acquisition of scientific literacy in physics is average because the score interval
(11-15) where the students’ mean, median and modal score falls to, which has a mid-point value of 13 and has
accounted for the highest frequency count of 102 students which is equivalent to 50% of the total number of 206
students assessed is the study. It also depicts that 58 students which is equivalent to 28% of the total students,
35
Journal of Education and Practice www.iiste.org
ISSN 2222-1735 (Paper) ISSN 2222-288X (Online)
Vol.6, No.7, 2015

score below the average group while a frequency count of 46 students which is equivalent to 22% of the total
students has accounted for those that score above the average.
Hence, this finding is justified to conclude that the overall acquisition of scientific literacy in physics among
senior secondary school students is average.

5.2 Research question 2: What is the reliability of the scientific literacy achievement test items?
Table 5: Reliability coefficient of items under each scale and overall items of the physics literacy test
Reliability Methods
SCALES Kuder-Richardson
Cronbach’s alpha Split-Half
(KR20)
SKI 0.353 0.358 0.374
SKII 0.570 0.573 0.556
SKIII 0.031 0.037 0.045
SHM 0.277 0.282 0.220
SPC 0.443 0.447 0.327
Overall 0.682 0.684 0.601
Average 0.70

Figure 4: Graphical illustration of the overall reliability coefficient of the achievement test items based on
the three methods of reliability estimates

Table 5 and figure 4 above presents the corresponding reliability coefficients of all the five scales in the literacy
achievement test as estimated by Cronbach’s alpha, Kuder-Richardson (KR20) and Split-Half method as 0.682,
0.684 and 0.601 respectively, while the average reliability based on the three methods for the Literacy
Achievement Test developed in this study is approximately 0.70.

Figure 5: Graphical illustration of the reliability coefficients of each scale of the achievement test based on
the three methods of reliability estimates

Cronbach’s alpha Kuder-Richardson (KR20) Split-Half

Figure 5 above presents the graphical illustration of the distribution of the corresponding reliability coefficients
36
Journal of Education and Practice www.iiste.org
ISSN 2222-1735 (Paper) ISSN 2222-288X (Online)
Vol.6, No.7, 2015

of each of the five scales in the literacy achievement test in accordance with Cronbach’s alpha, Kuder-
Richardson (KR20) and Split-Half methods respectively.

5.3 Research question 3: What is the difficulty index of the scientific literacy achievement test items?
Table 6: Distribution of items’ difficulty index
Difficulty index Cumulative Difficulty Item
No. of items Percent
range percent level evaluation
0.00 - 0.40 7 28.0 28.0 High Difficult
0.41 - 0.70 13 52.0 80.0 Moderate Good
above 0.7 5 20.0 100.0 Low Simple
Total 25 100.0

Table 6 above presents the distribution of difficulty index of all the twenty five (25) items in the achievement
test vis-à-vis their respective index range, the corresponding number of items in various ranges and percentage of
each difficulty level as well item evaluation. The table reveals that 7(28%), 13(52%) and 5(20%) items have
their difficulty index between 0.00-0.40, 0.41-0.70 and above 0.7 and evaluated to be difficult, good and simple
items respectively

Figure 6: Graphical illustration of the distribution of items’ difficulty index

Graphical illustration in figure 6 above further shows that 7(28%) of the items have low difficulty index value
hence they are regarded as being difficult items, 13 items which is equivalent to 52% of the total items have
moderate difficulty index, so they are refer to as Good items, while 5 items which is equivalent to 20% of the
total items have highest value of difficulty index, hence they are said to be simple items.

5.4 Research question 4: What is the discrimination index of the scientific literacy achievement test items?
Table 7: Distribution of discrimination index of the achievement test items
Discrimination No. of Valid Cumulative
Item evaluation
index items percent percent
above 0.40 2 8.0 8.0 Very Good
0.30-0.39 9 36.0 44.0 Reasonably Good
0.20-0.29 6 24.0 68.0 Marginal
Below 0.19 6 24.0 92.0 Poor
Negative value 2 8.0 100.0 Miskeyed
Total 25 100.0

Table 7 presents the distribution of discrimination index of the achievement test items. It shows that 2(8%) items
each have their discrimination index above 0.04 and as negative value, 6(24%) items each have discrimination
index falling into the range of 0.20-0.29 and below 0.19 while 9(36%) items have their discrimination index
between the ranges of 0.30-0.39.
37